Almost half the world's children face the prospect of growing up without proper schooling unless there is a "transformation" in the funding of education in the poorest countries, Gordon Brown has warned.
The former prime minister, who heads the International Commission on Financing Global Education Opportunity, said the shortage of schooling represented a "ticking time bomb" which could trigger new protest movements among a generation frustrated at the lack of life chances.
Mr Brown, who is presenting the commission's findings at the United Nations in New York, said 30 billion dollars (£23 billion) in additional funding was needed if the goal of ensuring every child receives a full primary and secondary education by 2030 is to be achieved.
While much of the funding will have to come from within the countries concerned, he acknowledged more would also be needed from the international community - including institutions like the World Bank as well as donor governments.
In particular, he called for an emergency injection of 400 million dollars (£305 million) for the estimated 30 million refugee children around the world - including four million who have fled the fighting in Syria - most of whom are not in school.
The commission estimates that by 2030, on current trends, 800,000 of the world's 1.6 billion children will not get a full education with 200,000 children receiving no formal schooling at all.
Mr Brown warned that failure of the international community to act could have profound consequences for the entire world.
"This is the civil rights struggle of our generation. At the moment we are betraying half our future," he told the Press Association.
"A time bomb is ticking. These young children denied an education will be a source of massive discontent in years to come.
"The gap between what they have been promised and what is actually delivered will be so great that it will cause Arab Springs and Occupy movements in the next generation if we fail to act.
"It is the basic instinct of every parent for their children to have the best possible start in life. The truth is that for half the children in the world we will not be offering them that unless we take the action that we are recommending."
Mr Brown, who is the UN special envoy for global education, said that low and middle income countries, which spent on average 2% of annual GDP on education, needed to raise that to around 5%.
At the same time, he said that there had to be a major reform of the international institutions with a new investment mechanism to channel funds into schooling.
He also called on donor governments to divert a greater proportion of their international aid spending to education projects, which currently accounted for just 10% of aid expenditure.
"We are calling for a complete transformation of the way we deal with education aid," he said.
"Aid has got to be more effective and it has got to be directed towards this priority of education. At the same time we need a new multilateral investment facility to direct resources into education."
Mr Brown said the implication of failing to deal with the issue were so serious, the commission was calling for the UN Secretary General to make an annual report to the Security Council with a new rapporteur reporting on violations of children's rights - such as child labour - which prevent them getting an education.